Ok so I have picked up an M3 for free this past week. It is in good shape, other than the fact that it makes no noise! When following the proper startup procedures, everything in the TWG spins freely, all the tubes light up, but no sound out of the speaker. I have read through the forum first to see if there was something simple that I have missed (ie drawbars in, or pedal up), but alas, no dice!</p>
Just hoping that some can offer some good advice.
</p>
I would think a dead power tube (a 6V6, the medium sized pair third and fourth from the left of the amp) except you say they all light up. So I'm left with what's been treated as a kind of insulting question: but do you have drawbars out and the expression pedal down?
1955 M3 (in good hands!)
1962 A100
1942 BC
too many other keyboards...
[quote user="redoctoberff"]I would think a dead power tube (a 6V6, the medium sized pair third and fourth from the left of the amp) except you say they all light up. So I'm left with what's been treated as a kind of insulting question: but do you have drawbars out and the expression pedal down?
[/quote]</p>
The amp should still sound
with one dead power tube. They both could be dead though, or the phase
inverter tube could be bad (V3 and V4, 2 tubes to the right of the
medium sized pair) </p>
Have you tried flipping the vibrato cancel tab? Could be a bad tube on the vibrato channel.
</p>
Make sure the speaker is plugged into the amp. Then remove all tubes and spray the pins and sockets with Deoxit. Reinsert tubes. Especially check the 12ax7. Be sure to generously oil the generator with Hammond Oil only.
Hammonds: A; AB; B3; D; E; 6-M3's; 2-A100; T582C.
Leslies: 3-31H; 21H, 22H, 4-44W; 46W; 25; 47; 45; 125; 50C; 51; 55C; 2-120; 122; 122A; 145; 147; 245; 770; 825; 2-102; 2-103; 300.
Wicks 2/5 pipe organ; Yamaha upright; Kurzweil Micro Piano & Micro B with M-Audio Oxygen 61; Yamaha DGX520; Wurlitzer 4100 (it came with a Leslie!). Peavey KB100 keyboard amp. Peavey Bass Guitar. Yes, I have A. D. (acquisition disorder) and don't want it cured.
This one sounds like a real basic fault. You said everything spins - did you check to make sure it *stays* spinning when you flip the run switch? Other than that, maybe a bad connection at the speaker, or an open voice coil?</P>
You can check that the TG is producing tones by tapping off the terminal strip on the back; alternately you can check the amp & speaker by plugging a known-good sound source into that little RCA "phono" input on the side of the expression pedal box.</P>
There's got to be a simple explanation here! [:)] I'd 10x rather have no output at all than an intermittent problem, for troubleshooting. We'll get this sorted, just keep testing and posting, testing and posting...</P>
good luck-</P>
td</P>
Nobody loves me but my mother,
And she could be jivin' too...
--BB King
Everything in the TG stays spinning on run. If I test the speaker using an alternate source of power, I can get noise through it, so I don't think it is the coil, or speaker.
</p>
Ok, checked the phono input by pluggin a CD player in....no luck. When you say tapping off the terminal strip to test thh TG, which terminals?</p>
If you're getting nothing through the amp, there is your problem. </p>
Just because a tube lights up, does not mean it is good. If you get nothing through the amp by plugging into the aux. input, I'll put my money on either V3 (the tube immediately to the right of the medium sized tubes) or V4 (the 12AX7 to the right of V3,) being bad. Those are the phase inverter tubes. If they are bad, the amp will not sound. </p>
Try swapping out the 12ax7 and see if that helps. If you have a buddy who plays guitar and has a tube amp, it's possible he has a spare laying around.
</p>
The outputs are in the front as you look at the picture - not the larger section at the very bottom (looks metallic in the picture), but the section immediately above it - looks kind of like a picket fence running across, right below the area with all the filter caps. There's another picture about halfway down captioned "Figure 5 - Main Generator Cover". If you look closely at that, along the very bottom you'll see the legend "Output terminal frequency numbers in consecutive order." That's what you want to find - just bear in mind the first view is kind of a quartering top view, and Figure 5 is a dead-on top view. (for that matter figure 6 shows it too.)</P>
All you do is rig up a test lead with one clip as "hot" or signal(i.e. tip if you're terminating in a mono 1/4" plug) and one as ground (i.e. sleeve on a 1/4" mono plug.) The hot clip can go to any one of those terminals; the ground can be clipped to any good solid metal point on the TG chassis. With this setup you should be able to confirm right away that you're getting tones out of the generator. If you are, and your speaker is definitely OK, then as others have suggested there's a fault in the amp somewhere.</P>
good luck-</P>
td</P>
Nobody loves me but my mother,
And she could be jivin' too...
--BB King
Tubes can light up and still be bad. The "light" you see is the low voltage filament--one could still have a short or a spent cathode. My first tube to suspect would be the 5U4 rectifier. When a rectifier goes you get zilch; when the others go you usually get low output, weird noises, etc. </p>
If you satisfy that the tubes are all good and the speakers are connected, the next step might be to have a look under the amp and check for anything burned or loose (poke at things with a chop stick.)
</p>
In addition, many tubes such as 12AU7 and 12BH7 are actually dual section tubes, and it is possible for the heater on one section to be bad. The heater on the other section would still light up, giving the appearance of a good tube, even though one section is dead.
1937 Model E
PR-40 w/Accutronic Reverberation
Leslie 31-H
Schulmerich ChimeATron
Ok, so it has been a while since my last post....but I now have replaced all my tubes, but still no noise. What do you all think would be the next logical place to be looking for solutions? Thanks.
My Hammond is "just a solid state" tone generator thing, but while I've been tinkering with it I have learned that just one bad old electrolytic cap can make the organ silent. Mine is from 1968 and I had to change many caps to make it work right. </P>
I would check all the caps first to see if they look allright after checking all the wires and connections (which you have done already...?) </P>
If you don't have the schematics for your M, I can send you one with the service manual.</P>
Check all the wires and caps. If you have changed the tubes and the TWG is turning, that's the only possible cause...</P>
Cheers,</P>
Jussi</P>
E-333 (modified)
Leslie 147 (surprise, not modified...)
Previous:
T-200 (modified and sold)
T-500 (modified and sold)
Thanks for the reply...I am assuming you are talking about the caps on the amp, and not the tonewheel? It may sound like a dumb question, but other than visually inspecting them, what is the best method for testing an electrolytic capacitor?</p>
Thus far, I have been able to determine that the tonewheel spins, the speaker works (from another source), all of the tubes have been replaced, and all light up, but I cannot get any signal through the amp (including through the phono jack).</p>
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